The intense and ongoing debate on physicians' right to refuse requested life-prolonging medical interventions highlights one of the emerging problems in modern medicine: the limits, if any, to a patient (or proxy's) claim to requested treatment. How is the physician to respond to requests for treatment believed by the physician to be futile, ineffective, or inappropriate? Three cases, Baby L, the extracorporeal membrane oxygenation (ECMO) baby, and Baby K, help focus the ethical and legal issues in this debate.